No idea what ingredients you’d get from kelp farming but it would be cool
Also aquaculture would be cool. You could farm fish (the fish would never be able to leave their cube sadly) and when they grew up you could cook them as food or compact them to get bones (like in Conan Exiles). We definitely could use a way to farm bones.
But yes, this all sounds lovely, fishies in the water please, we can fish them, keep them in separate little areas, etc.
Oh, oh, oh! Just had a nice idea! One of the fish we can keep in a pond and farm them is a really, really fast one which is hard to catch but once you have a bunch of them in an enclosed little pond they reproduce like maniacs and once they die they drop… wait for it… adrenal glands! (or something else that can be used instead of adrenal glands, perhaps their eggs can so we need to decide to use the eggs to create more fish or use them up in a recipe for fast brews!)
And growing kelp and other water plants sounds very good too! Reactive lamellas could be grown like that!!
Hm what if you could compact meat to get bones? Maybe 2 regular meat to one bone, 1 prime meat to one bone.
Also it would be more interesting if harvesting plants then putting them in the extractor gave more output than “doing it in the field” by hitting the plant with a hammer.